Production method of superclean wiping cloth

ABSTRACT

Disclosed is a production method of superclean wiping cloth, including the steps of choosing filament, weaving, removing oligomers and dust particles through rinsing process, dehydrating, setting, cutting, washing, drying, and packaging; wherein removing oligomers and dust particles through rinsing process is the key process, the airflow rinsing machine is used to rinse the gray fabric, avoiding the reverse contamination and cloth damage during washing, ensuring a high cleanliness of the gray fabric. Excellent effect of removing oligomers and dust particles will be achieved through adding degreasers of specific formula, in a clean environment, at a specific temperature, whereby a wiping cloth product with stable quality, i.e., real superclean wiping cloth, will be obtained. The rising process is simple and highly efficient, it ensures the stability of product quality and high cleanliness, producing a superclean wiping cloth with high cleanliness and stable quality, using a simple and efficient production process.

TECHNICAL FIELD

The present application relates to the technical field of supercleanwiping cloth, especially a production method of superclean wiping cloth.

BACKGROUD OF THE INVENTION

Wiping cloth have soft surfaces which are suitable for wiping thesensitive surface of object, they do not lose fibres during rub, andhave good water-absorbing property and clean efficiency. In view ofabove advantages, the wiping cloth are widely applied, e.g., in thefields of production lines of semiconductor chip, microprocessor, etc.,disk driver, composite material, display product such as LCD, productionline of circuit board, precise instrument, optical production, aviationindustry, PCB product, medical instruments, laboratory, dust-free plant,etc. All the time nonvolatile residues and dust particles residues aresignificant factors effecting the application of wiping cloth. Theresidual amount of the nonvolatile residues (NVR value) and the residualamount of the dust particles residues (LPC value) affect the applicationscope of dust-free cloth. For example, in the optical industry, if theNVR value of wiping cloth is too high, the light transmittance will beaffected and the emission efficiency will be decreased, whereby manyproblems will be caused, such as high energy consumption of device, poorstability and display quality, etc. In high-end industries, the NVRvalue of wiping cloth is normally required not more than 0.05 mg/g, andthe LPC value is normally required not more than 50 counts/cm². The keyprocess to affect the cleanliness of wiping cloth is the rinsing processof woven gray fabric. In the current rinsing process, ordinary wellwater, river water or tap water, which contains large amount of ions andimpurities, is generally used, this cannot enhance the cleanliness ofcloth greatly. The improved rising process is normally as follows:injecting the pure water into an overflow rinsing vat, and adding somechemical detergents therein to rinse the gray fabric in an intermittentcirculating rinse way. However because of the disadvantages of overflowmachine itself, and low cleanliness of the water used, the cleanlinesswill varies largely in the produced wiping cloths, so it is difficult toguarantee the production quality, that is, it is difficult to ensure theNVR value is not more than 0.05 mg/g, and LPC value is not more than 50counts/cm². The wiping cloth with low cleanliness has poor stain removalproperty, which will harm the devices, sensitive materials, etc., evenshorten the service life of the devices and materials, if it is appliedthereto in a long term.

Therefore, a superclean wiping cloth with high cleanliness and stablequality, along with simple and efficient production process must beprovided.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a production method ofsuperclean wiping cloth, producing a superclean wiping cloth with highcleanliness and stable quality, in a simple and efficient productionprocess.

The present invention provides a production method of superclean wipingcloth, comprising the steps of

-   -   A. Choosing filaments: choosing continuous filament yarn above        AA grade, wherein the oil content of yarn is lower than 1.5%;    -   B. Weaving: weaving the filament from step A to form a gray        fabric, in environment of ISO 1 to ISO 9 grade, the fabric is        woven by weave of 28-42 stitches, double knit weave, weave of        1/1, ½ or ⅓, or the combination of the mentioned two or three        weaves;    -   C. Removing oligomers and dust particles through rinsing        process: rinsing the gray fabric from step B circularly by high        temperature pure water, using an airflow rinsing machine without        reverse contamination as a boiling-off rinsing equipment, at a        water temperature of 80° C. to 130° C. , adding degreasers, such        as surfactant, enzyme catalyst, sodium carbonate, sodium        percarbonate, or sodium hydroxide, in order to remove oligomers,        wherein the surfactant is 0.1% to 0.8% by weight, the sodium        carbonate is 0.2% to 1% by weight, the sodium percarbonate is        0.2% to 1% by weight, the sodium hydroxide is 5 g/L to 20 g/L,        the bath ratio of gray fabric to the rinsing solution is 1:3 to        1:10, removing oligomers and dust particles on the gray fabric        in high temperature condition by using airflow rinsing machine;    -   D. Dehydrating: dehydrating the oligomer-free and dust-free gray        fabric by using a rotating centrifugal purification dehydrator,        removing ions, dust particles and other dirt from the fiber        surfaces of gray fabric, wherein the rotating centrifugal        purification dehydrator has a dehydrating part made of 316        stainless steel, the dehydrating rotating speed is 350 to 600        rpm;    -   E. Setting: setting the gray fabric by a dust-free and silicone        oil-free setting machine in an environment above ISO 8 grade, in        the totally enclosed mode, at a temperature from 160° C. to 210°        C., with a setting speed of 30 to 60 m/min;    -   F. Cutting: putting the gray fabric after setting into the        dust-free room above ISO 7 grade, cutting the gray fabric        through ultrasonic wave cutting, laser cutting, or thermal        cutting, to form a preliminary wiping cloth;    -   G. Washing: washing the wiping cloth after cutting in an        environment above ISO 5 grade, by using a roller or spray        washing, for 3 to 5 times, 5 to 10 minutes each time, wherein        the bath ratio of wiping cloth to washing solution is 1:10 to        1:20;    -   H. Drying: drying the washed wiping cloth at a temperature of        70° C. to 95 ° C., using purified hot gas spraying process or a        roller;    -   I. Packaging: packaging the wiping cloth in the dust-free room        above ISO 5 grade, preferably above ISO 4 grade.

Preferably, the gray fabric in step B has yarn densities as follows:warp density is between 150 to 230 yarns/inch, preferably 180yarns/inch; weft density is between 80 to 120 yarns/inch, mostpreferably 100 yarns/inch.

Preferably, the rinsing process in step C is performed in an environmentabove ISO 8 grade, the pure water, the resistance of which is more than18M ohm, is selected from purified water or RO water or ultrapure water.In step C, the gray fabric is circulated 5 to 12 times in the hightemperature pure water.

Preferably, if the yarns are superfine fibers, the rinsing effect willbe optimum when the water temperature in step C is 110° C. ±3° C. if theyarns are dacrons, the rinsing effect will be optimum when the watertemperature in step C is 100° C. ±3° C.

Preferably, the surfactant is 0.3% by weight, the enzyme catalyst isjust a small amount, the sodium carbonate is 0.5% by weight, the sodiumpercarbonate is 0.5% by weight, the sodium hydroxide is 10 g/L.

Preferably, the dehydrating rotating speed of the rotating centrifugalpurification dehydrator in step D is 400 rpm.

Preferably, the temperature of the setting in step E is 200° C., and thesetting speed is 45 m/min.

Preferably, a nonvolatile residue test is applied on the wiping clothmanufactured through step A to step I, the NVR value of the wiping clothis not more than 0.05 mg/g. A liquid dust particles test is applied onthe wiping cloth manufactured through step A to step I, the LPC value ofthe wiping cloth is not more than 50 counts/cm².

The present invention provides a production method of superclean wipingcloth, the rinsing process of the woven gray fabric is the key processin the whole production process. In the rising process, the airflowrinsing machine is used to rinse the gray fabric, avoiding the reversecontamination during washing and unwanted damage due to overmuch processcirculation, and ensuring a high cleanliness of gray fabric afterrinsing. Excellent effect of removing oligomers and dust particles willbe achieved through adding degreasers of specific formula into theairflow rinsing machine, in a clean environment, at a specifictemperature, whereby a wiping cloth product with stable quality, i.e., areal superclean wiping cloth, will be obtained. The rising process issimple and highly efficient, it ensures the stability of product qualityand high cleanliness, producing a superclean wiping cloth with highcleanliness and stable quality, using a simple and efficient productionprocess.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a schematic diagram of the technological process ofthe production method of superclean wiping cloth according to oneexample of the present invention.

The present invention will be further described in detail hereinafterwith reference to the accompanying drawing.

DETAILED DESCRIPTION OF THE INVENTION

It should be understood that the preferred embodiment discussed hereinare only for illustrating the present invention, but not to limit theinvention.

As shown in FIG. 1, an example of the production method of a supercleanwiping cloth according to the present invention is provided here, themethod comprises steps of

A. choosing filaments;

B. weaving;

C. removing oligomers and dust particles through rinsing process;

D. dehydrating;

E. setting;

F. cutting;

G. washing;

H. drying; and

I. packaging.

The step A to step I are described in detail as follows.

Step A. Choosing filaments: choose continuous filament yarn above AAgrade, wherein the oil content of yarn is lower than 1.5%.

Step B. Weaving: weave the filament from step A to form a gray fabric,in the environment of ISO 1 to ISO 9 grade, wherein ISO 9 grade is themost clean grade, and the environment should be as clean as possible.The fabric is woven by weave of 28-42 stitches, double knit weave, weaveof 1/1, ½ or ⅓, or the combination of the mentioned two or three weaves.Wherein the specific number of stitches can be selected based on theactual requirement. The gray fabric has yarn densities as follows: warpdensity is between 150 to 230 yarns/inch, preferably 180 yarns/inch;weft density is between 80 to 120 yarns/inch, preferably 100 yarns/inch.

Step C. Removing oligomers and dust particles through rinsing process:rinse the gray fabric from step B circularly by high temperature purewater, using an airflow rinsing machine without reverse contamination asa boiling-off rinsing equipment, at a water temperature of 80° C. to130° C. If the yarns are superfine fibers, the rinsing effect will beoptimum when the water temperature in step C is 110° C. ±3° C. If theyarns are dacrons, the rinsing effect will be optimum when the watertemperature in step C is 100° C. ±3 ° C. Add degreasers, such assurfactant, enzyme catalyst, sodium carbonate, sodium percarbonate, orsodium hydroxide, in order to remove oligomers, wherein the surfactantis 0.1% to 0.8% by weight, the sodium carbonate is 0.2% to 1% by weight,the sodium percarbonate is 0.2% to 1% by weight, the sodium hydroxide is5 g/L to 20 g/L. Preferably the surfactant is 0.3% by weight, the enzymecatalyst is just a small amount, the sodium carbonate is 0.5% by weight,the sodium percarbonate is 0.5% by weight, the sodium hydroxide is10g/L. The bath ratio of gray fabric to the rinsing solution is 1:3 to1:10, the rinsing process is performed in an environment above ISO 8grade, the pure water is selected from purified water or RO water orultrapure water, the gray fabric is circulated 5 to 12 times in the hightemperature pure water, certainly the number of circulation will dependson the cleanliness of the gray fabric.

Rinsing conditions, such as temperature, lasting time, etc., and theformula of degreaser are determined by more experiments through computerprocess, whereby the optimum effect of rinsing process will be obtained,such that the oligomers and dust particles can be efficiently removed,and a high cleanliness of the gray fabric after rinsing will beachieved.

An ordinary overflow rinsing machine will carry various contaminantsafter a long-term use, and the contaminants can contaminate the grayfabric easily during rinsing process, leading to a reversecontamination. In the present invention, an airflow rinsing machine isused to rinse the gray fabric, avoiding the reverse contamination duringrinsing process, ensuring a high cleanliness of gray fabric afterrinsing process.

In addition, the rinsing process for the woven gray fabric is the mostimportant process during the production of wiping cloth. In the risingprocess, airflow rinsing machine is used to rinse the gray fabric,avoiding the reverse contamination during rinsing process, and ensuringthe high cleanliness of gray fabric after rinsing. Meanwhile excellenteffect of removing oligomers and dust particles will be achieved byadding degreasers of specific formula into the airflow rinsing machine,in a clean environment, at a specific temperature, whereby a wipingcloth product with stable quality, i.e., real superclean wiping cloth,will be obtained. The rising process is simple and highly efficient, itensures the stability and high cleanliness of the product, making a realsuperclean wiping cloth having high cleanliness and stable quality,using a simple and efficient process.

Step D. Dehydrating: dehydrate the oligomer-free and dust-free grayfabric by using a rotating centrifugal purification dehydrator, whereinthe rotating centrifugal purification dehydrator has a dehydrating partmade of 316 stainless steel, the dehydrating rotating speed is 350 to600 rpm, preferably 400 rpm. Ions, dust particles and other dirt can beremoved from the fiber surfaces of gray fabric efficiently.

Step E. Setting: set the gray fabric by using a dust-free and siliconeoil-free setting machine in an environment above ISO 8 grade in thetotally-enclosed mode, at a temperature from 160° C. to 210° C.,preferably 200° C., with a setting speed of 30 to 60 m/min, preferably45 m/min.

Step F. Cutting: put the gray fabric after setting into the dust-freeroom above ISO 7 grade, and cut the gray fabric through ultrasonic wavecutting, laser cutting or thermal cutting, to form a preliminary wipingcloth;

Step G. Washing: wash the wiping cloth after cutting in an environmentabove ISO 6 grade, by using a roller or spray washing, for 3 to 5 times,5 to 10 minutes each time, wherein the bath ratio of wiping cloth towashing solution is 1:10 to 1:20.

Step H. Drying:dry the washed wiping cloth at a temperature of 70° C. to95° C., using purified hot gas spraying process or a roller.

Step I. Packaging: package the wiping cloth in the dust-free room aboveISO 5 grade, preferably above ISO 4 grade.

The environment for packing can be chosen according to actualrequirement for products. After the packaging process, the productionprocess of wiping cloth is finished.

Nonvolatile residue test (NVR test) is a test method to measure thecontent of nonvolatile residues on the wiping cloth. When testing, acertain amount of solvent is used to immerse a predetermined testedcloth, then collect the solution, evaporate the solvent, and weight theresidue using a micro balance, whereby the NVR value can be obtained(the detailed method is performed according to IESTCC004.3) afterconversion. NVR test is applied on the wiping cloth manufactured by theabove processes, NVR value of the wiping cloth is 0.03 mg/g, and it isobvious that such NVR value is no more than 0.05 mg/g, so itscleanliness is better than the industry standard.

Liquid dust particles test (LPC test) is an important method to measurethe cleanliness of wiping cloth. LPC test is applied on the wiping clothmanufactured by the above processes, the LPC value of wiping cloth isnot more than 28 counts/cm², and it is obvious that such LPC value isnot more than 50 counts/cm², so the cleanliness is better than theindustry standard.

It is certified by the NVR and LPC test that the cleanliness of wipingcloth manufactured by the production process according to the presentinvention is greatly better than the relevant standard of the wipingcloth, and such wiping cloth is a real superclean wiping cloth.

The embodiments described hereinbefore are merely preferred embodimentsand not for purposes of any restrictions or limitations on theinvention. Therefore, equivalent reconfiguration according to thedescription and drawings of the present invention, or by directly orindirectly applying other relevant technical field, may be incorporatedinto ambit of the present invention.

1. A production method of superclean wiping cloth, comprising the stepsof: A. Choosing filaments: choosing continuous filament yarn above AAgrade, wherein the oil content of yarn is lower than 3.5%; B. Weaving:weaving the filament from step A to form a gray fabric, in theenvironment of ISO 1 to ISO 9 grade, the fabric is woven by weave of28-42 stitches, double knit weave, weave of 1/1, ½ or ⅓, or thecombination of the mentioned two or three weave; C. removing oligomersand dust particles through rinsing process: rinsing the gray fabric fromstep B circularly by high temperature pure water, in environment aboveISO 8 grade, the pure water, the resistance of which is more than 18Mohm, is selected from purified water or RO water or ultrapure water, thegray fabric is circulated 5 to 12 times in the high temperature purewater; using an airflow rinsing machine without reverse contamination asa boiling-off rinsing equipment, at a water temperature of 80° C. to130° C.; adding degreasers, such as surfactant, enzyme catalyst, sodiumcarbonate, sodium percarbonate or sodium hydroxide in order to removeoligomers, wherein the surfactant is 0.1% to 0.8% by weight, the sodiumcarbonate is 0.2% to 1% by weight, the sodium percarbonate is 0.2% to 1%by weight, the sodium hydroxide is 5 g/L to 20 g/L, the bath ratio ofgray fabric to rinsing solution is 1:3 to 1:10; removing oligomers anddust particles on the gray fabric in high temperature condition by usingairflow rinsing machine; D. dehydrating: dehydrating the oligomer-freeand dust-free gray fabric by using a rotating centrifugal purificationdehydrator, and removing ions, dust particles and other dirt from thefiber surfaces of gray fabric, wherein the rotating centrifugalpurification dehydrator has a dehydrating part made of 316 stainlesssteel, and its dehydrating rotating speed is 350 to 600 rpm; E. setting:setting the gray fabric by using a dust-free and silicone oil-freesetting machine in an environment above ISO 8 grade, in thetotally-enclosed mode, at a temperature from 160° C. to 210° C., with asetting speed of 30 to 60 m/min; F. cutting: putting the gray fabricfrom step E into the dust-free room above ISO 7 grade, and cutting thegray fabric through ultrasonic wave cutting, laser cutting or thermalcutting, to form a preliminary wiping cloth; G. washing: washing thewiping cloth from step F in environment in or above ISO 5 grade, byusing a roller or spray washing, for 3 to 5 times, 5 to 10 minutes eachtime, wherein the bath ratio of wiping cloth to washing solution is 1:10to 1:20; H. drying: drying the washed wiping cloth at a temperature of70° C. to 95° C., using purified hot gas spraying process or a roller;I. packaging: packaging the wiping cloth in the dust-free room above ISO5 grade, preferably above ISO 4 grade.
 2. The production method of claim1, wherein said gray fabric in step B has yarn densities as follows:warp density is 150 to 230 yarns/inch, preferably 180 yarns/inch; weftdensity is 80 to 120 yarns/inch, preferably 100 yarns/inch. 3.(canceled)
 4. The production method of claim 1, wherein if said yarnsare superfine fibers, the rinsing effect will be optimum when watertemperature in step C is 110° C.±3° C. if said yarns are dacrons, therinsing effect will be optimum when water temperature in step C is 100°C.±3° C.
 5. The production method of claim 1, wherein preferably thesurfactant is 0.3% by weight, the enzyme catalyst is just a smallamount, the sodium carbonate is 0.5% by weight, the sodium percarbonateis 0.5% by weight, the sodium hydroxide is 10 g/L.
 6. The productionmethod of claim 1, said dehydrating rotating speed of said rotatingcentrifugal purification dehydrator in step D is preferably 400 rpm. 7.The production method of claim 1, wherein said temperature in step E ispreferably 200° C., and the setting speed is preferably 45 m/min.
 8. Theproduction method of claim 1, wherein a nonvolatile residue test isapplied on the wiping cloth manufactured through step A to step I, theNVR value of the wiping cloth is not more than 0.05 mg/g; a liquid dustparticles test is applied on the wiping cloth manufactured through stepA to step I, the LPC value of the wiping cloth is not more than 50counts/cm².